People are vegetarians for a variety of reasons. Some simply dislike the taste of meat products, while for others it is ethical or cultural aspects that are important. Whatever the reason, it seems a major benefit that many vegetarians enjoy is better health.

A recent large-scale investigation supports this. The Adventist Health Study in North America looked at dietary information for 73,000 men and women who were followed for 5 years. These were grouped into categories according to their diet: nonvegetarian, semi-vegetarians (i.e. people who eat meat or fish but at most once a week), vegetarians who eat fish, vegetarians who eat eggs and dairy products, and vegans.

Around 2,500 of these people died during the study period, and the researchers were able to compare the number of people in each diet group who died. Overall – after correcting for other factors that might have had an influence – the results suggested that vegetarians were about 12% less likely to die of any cause during the period than the meat eaters. The group that came out best were the vegetarians who also ate fish, and the vegans also did well. The benefits seemed to be greater for men than women.

In particular, the vegetarians were less likely to die from cardiovascular, kidney and endocrine diseases. Interestingly, the researchers didn’t find a difference in the number of deaths from cancer.

Studies like these cannot prove definitively that vegetarianism was the cause of people living longer: there is always the possibility of some hidden factor not taken into account. But this was a large study carefully carried out, and it does seem to support the health benefits of a vegetable-based diet. At the very least it should help vegetarians strengthen their resolve to continue, and give the rest of us reason to think about what we eat.

There is other evidence that cutting back on meat-eating is a good idea (see, for example, Meat and Diabetes). But it is worth remembering that changing other aspects of your diet – such as cutting back on salt and sugar, eating plenty of vegetables and fruit, and looking after your body weight – may have as great an impact on your health.